math...答我一題都好...好趕

１．2[3x(x-2)]=3[2x(x-1)]+12
6x^2-12x=6x^2-6x+12
-6x=12
x=-2
2. 2(x-2)-3(x-1)-5=3-5(x+1)
2x-4-3x+3-5=3-5x-5
-x-6=-5x-2
4x=4
x=1
3.3over2(x+1)-5over6=-1over3(x-2)
9(x+1)-5=-2(x-2)
9x+4=-2x+4
x=0
4.let x be the required number
5x-4=3x
x=2
therefore the required number is 2.

唔知有冇錯你自己驗算下

講得好